Facebook has rolled out free voice calling over Wi-Fi and cellular data within its Messenger app for users in the US, after testing it for a short time in Canada.

To begin using the feature, users don't have to download an update through the App Store - the voice calling feature simply appears. 

Initiating a call is easy by just tapping the "i" button in the top-right corner of chat with another user. The user on the other end will receive a push notification to accept or refuse the call. 

We can see this feature being especially useful for customers who want to save their voice minutes. There are other solutions like Skype and Vonage, but Facebook has all of your friends in one convenient place.

Earlier this month, Messenger was updated on iOS and Android with a feature that allows users to send voice messages within the app.  "Just tap '+' next to the box where you write a message, then tap 'Record' and hold down the record button to talk.  When you're ready to send, just release the button," Facebook explains, on how to use the new feature.

Facebook told Pocket-lint there were "no further details on international or Android at this time".